A drum motor (sometimes referred to as a motorised pulley) is a geared motor drive enclosed within a tubular shell (the drum shell or the drum tube) providing a single component driving pulley for conveyor belts. A drum motor typically comprises a motor (e.g. electric or hydraulic) fixed to a stationary shaft at one end of the drum and directly coupled through the motor's rotor pinion to an in-line gearbox which is fixed to the other stationary shaft. The torque is transferred from the motor via the gearbox to the drum shell through a coupling or geared rim attached to the shell or end housing. The only moving external parts are the drum shell and bearing housings. The power required by the motor is provided through one of the stationary shafts. The exposed drum shafts are used to install and fix the drum motor into the conveyor frame and do not rotate. Lubrication of the drum motor is achieved with oil and/or grease whereby the oil may also help to cool the motor. Each end of the drum shell is sealed with some sort of lid to keep the oil in the interior of the drum tube and to prevent water, dust and dirt to reach the inside of the drum motor.